Add ARM64 Windows to configure scripts

In order to correctly configure for Windows 10 on ARM, this change adds
a --target value arm64-win64-vs15 to ./configure and adds feature
enable/disable logic for the new platform.

This is merely sufficient for Chromium targeting ARM64 Windows.

Bug: 893460
Change-Id: I46194286f63104bdf6ac57d719fdf1e5d5fa72c8
3 files changed